| 摘要 |
<p>953,790. Control of A.C. motors. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. Feb. 22, 1963 [March 20, 1962], No. 10634/62. Heading H2J. An induction motor M is reversed by disconnecting the motor from three-phase supply S and by alternatively connecting the motor to a capacitor network CR having a reactance comparable to the short-circuit reactance of the motor. The motor is self-excited as it decelerates and the capacitors of the network ensure that the frequency of the motor voltage decreases with speed, thereby providing a braking operation. When the speed falls to a predetermined value, voltage-sensitive relay VR releases to disconnect the motor from network CR, and to reconnect the motor to the source S for reverse driving operation.</p> |
